Just curious about what to expect... I am test fitting a 35x12.5R18 General Grabber AT2 Tuesday, and if all is good, will probably be fitted with them by Saturday. They don't have in stock and would only get one before I commit to buy.

So how would you expect these type tires would affect mpg? It isn't a big deal really, I just didn't want to be shocked that my avg mpg back and forth to work drops from current 16-17mpg to 10 or something lol. After all, I did install a supercharger that requires premium to my Mustang with little regard to mpg... but it still gets 25 on highway, so the F150 can't compete!

Of course depending on fit, may end up with 33's, much difference in mpg between 35 and 33?

2006 KR with 2.5" leveling kit, using stock wheels

Thanks

 

I average about 12 mpg with my 35's.

 

I'm getting mid 14's according to the computer.

 

I get 15 combined on mine. But I do have 4.56 gears

 

Quite the ranges here, which I understand lots of variances such as drive habits and city / hiway travel. Can anyone provide before / after for a better estimation?

FWIW, I have 3.73. My daily commute is 55mph hiway traveling thru 2 one stop light towns down to 35 mph. This is when I avg close to 17...weekend driving around town obviously trends down. All based on trip computer.

 

i get about 11. but thats my fault.

 

its all in how you drive it. it will drop some, how much is up to you. you cant sit here and listen to other peoples numbers and think it will be the same for you. my brothers lifted f150, 5.4, 37's, 22's, i can average 16 mpg with a 50/50 city highway mix. its all how you drive it.

 

Have any of you reprogrammed? If not, all of those readings are off. Bigger tires throw off the odometer, which in turn throws off the fuel mileage. Only true way to figure it out without reprogramming is keep track of mileage wiht a GPS and then divide that mileage by the total gallons used.

My 2005 with 3.73s and 35s tells me 13 all the time. But that is without being reprogrammed.

 

Right. A lot of people see a big drop in their MPG's and freak out, but their calculations are off if they havn't corrected their speedometer/odometer.
Also, I get 13 MPG combined city/highway with 35's and 3.55 gears.

 

I'd say about a 2 mpg loss in stop and go city driving and about a 1 mpg loss on the highway. Performance loss is what got me but a programmer can make it a little more bearable. I find a close to 34 inch tall tire is a better compromise for look's and performance. Just my 2 cent's.

 

I have a Troyer xcal but don't know how to reprogram the speedometer. Anyone want to tell me how so I can feel better about my mpg?

 

Thanks everyone for the replies. I do have a programmer, Gryphon, so will be able to adjust for tire size

 

Getting excited, the test fit went fine, no rubbing at all. They only had the one tire, should have other three by Friday, planning a Saturday morning install.

Sorry for crappy cell phone pic

 

I just put on the 35" General Grabber ATs as well. I have put a little over a 1000 miles on them and so far I'm impressed. Very quiet and feels like my truck rides better. I went from an avg of 16 mpg on the computer to around 14. I don't have a programmer so I know thats not accurate. At least I'm putting less miles on my truck now. I've got a couples of pics in my profile if you want to check them out.

 

Fill up your truck, reset the odometer. Next fill up, divide by the trip odometer. I'm an IT dude by trade, but I don't trust the Ford trip computer for MPG estimates.

Those tires look sweet.